The invention comprises an imaging system forming a pseudoscopic image in focus throughout extended depth of field comprising an input relay lens array, a double integral microlens screen having a median plane on to which the input lens array images an object scene and, on the opposite side of the screen and the same distance therefrom as the input array, an output relay lens array similar to the input lens array.
The relay lenses are substantially larger than the screen microlenses.
The double integral microlens screen may comprise a monolithic screen having back to back plano-convex lens arrays either side of the median plane each of focal length equal to half the screen thickness.
The double integral microlens screen may however comprise two similar contiguous screens each comprising double convex microlenses each having a thickness equal to the focal length.
An optical instrument comprising such an imaging system may have fixed components for dedicated use or may be adjustable, the input and output relay lens arrays being mounted for equal and opposite adjustment with respect to the double integral microlens screen.